HP 5300 - Manual (Page 147)

Questions and Answers
H-4 HP Smart Array 5300 Controller User Guide
HP CONFIDENTIAL
Writer: Jennifer Hayward File Name: r-apph questions and answers
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Also, HP offers a unique Pre-Failure Warranty for all drives—valid only when using
HP or Compaq branded drives, HP or Compaq branded array controllers, and Insight
Manager. Contact your dealer for more information about the HP Pre-Failure
Warranty.
Q: Why do the drive activity LEDs light up on some drives when my system is
idle?
A: The Smart Array controller performs several different background activities on
the drives when the controller is otherwise idle. For example, Auto-Reliability
Monitoring scans fault-tolerant volumes for defects and verifies the consistency of
parity data, and Drive Parameter Tracking periodically checks the performance of all
drives on the controller (normally on an hourly basis).
Q: What is RAID ADG?
A: RAID ADG is an extension of RAID 5 that allows additional fault tolerance by
using two different and independent parity schemes. Data is striped across a set of
hard drives, just as with RAID 5, and the two sets of parity data are calculated and
written across all the drives in the array.
RAID ADG provides an extremely high level of fault tolerance and can sustain two
simultaneous drive failures without downtime or data loss. This fault tolerance level
is the perfect solution when data is mission critical.
Not all controllers support RAID ADG.
Q: How is RAID ADG activated?
A: RAID ADG is activated by means of a software key that you install on the
controller. This software key is available as a separate option kit, and it is suitable for
all model SA5304 controllers.
Older versions of the Smart Array 5304 Controller also allow you to activate RAID
ADG by using a hardware key (the RAID ADG Enabler Module) and a firmware
upgrade.